How to check your mobile number. ?

Hi Friends whenever you buy new SIM card, then it will take times for u to heart your new number.Some time you did’t remember your new number and forgot them whenever some body ask your new number.you always give a call to your friends mobile number and ask your new number but it is a long process and take much time. you can use the some codes and Check your own mobile number for major network providers without wasting time.